Pangea AC14XL removeable ground plug

cleeds835 posts10-04-2017 7:23am brf

Using a cheater plug or removing the ground pin are both a safety hazards and should only be used to identify a ground loop problem. Removing the safety ground should never be implemented as a solution.

+1. Removing a safety ground treats only the symptom of the problem, rather than addressing its root cause. With proper grounding methods - such as star grounding - there’s no reason to limit safety in the interest of reducing noise or hum.

Agree!

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@ alexlhsu,

What other associated audio/video equipment is connected ahead of the amp?
Just because you lifted the safety equipment chassis ground from the amp, by removing the ground pin from the AC power cord plug, doesn’t mean the amp is the cause of the ground loop/ground loop hum. Removing the ground pin only broke, opened, the completed ground loop circuit thereby stopping the hum. The offending piece of equipment causing the ground loop could be upstream from the amp.

Through the process of elimination you should be able to find the culprit.
Start with only the power amp and preamp connected together with interconnects. Disconnect all other pieces of front end equipment from all the inputs of the preamp. Unplug all the other equipment from the AC power receptacle outlets.

Power up the preamp and power amp and check for hum.
If hum, are both pieces plugged into the same AC power duplex receptacle outlet? If not, do so and then check for hum.

IF no hum, connect one piece of front end equipment to the inputs of the preamp and check for hum.

Jim

Thank you all for the feedback.  EBtech works for my other amp (a custom made integrated tube) but not perfect with this Passlabs X150 (still have a very low audiable noice).  The other equipments are Passlabs X2.5 preamp and an Audio Technica turntable with build in phono amp, speakers are B&W 805, interconnects are Kimber Kable Silver Steak RCA and KCAG XLR, speaker cable is Kimber Kable 8TC; amp power cords were Cardas now replaced by Pangea (kept the ground pin to preamp) and Audio Prism power foundation.  Yeah, there is really no difference removing the ground pin or using a cheater plug, it’s an ego thing:-).  I used to use Proceed processor and Passlabs X250+X3 for B&W 802, 805 and HTM1, same hum, and started using cheater plugs for many years (followed Passlabs supoport advice, didn’t check all the equipments).

My tube amp is only connected to an Audioengine B1 Bluetooth adapter and B&W CM1 for bed time listening from iPad; Cardas power cord, no hum with EBtech.

There are only two other powered equipments so it would be easy to check if any one or both of them contributing to the hum.

Appreciate all your inputs and help.

Regards

PS:  has anybody connected powered subwoofer to your 2 channel system?  I have a B&W PV1D active subwoofer sitting there doing nothing.  I sold all the multi-channel gears a few years ago, returned to near field 2 channel but kept this brand new subwoofer thinking maybe I will miss the low end base from the 802 I sold and use it to augment the 805.  I recently started to listening more classic rock and was wondering how it would sound if I added that subwoofer.

Possible bingo ... are you using the AT TT's built in pre-amp?  That can be the source of the hum.  Are you using the built-in or outboard pre-amp?

https://www.youtube.com/watch?v=4NT67ii04uQ

Rich 

I would really like to learn WHO at Pass suggested you use a cheater plug. They are not safe.

If they were safe, every amp would have a ground lift switch for the power cord.

Oddly enough, Parasound puts a ground lift switch on their Halo amps.  When I had the A21, I never had to use it.  I used to get a very slight hum coming from the amp occasionally, and I chalked it up to flourescent light fixtures that were on the same circuit.  

When I upgraded those fixtures with new ballasts, the noise went away.